Many surgical procedures result in a foreign body being removed from a patient. In some instances, the foreign body is inadvertently dropped or misplaced in the body by a medical professional. In other instances, the foreign body the foreign body needs to be removed due to the presence of infection or likelihood that it will spread.
Implantable objects require removal for a variety of reasons including wear, rejection by the patient or infection. Stents are commonly inserted for a variety of medical reasons such as the prevention of tubular passage occlusions. Stents may be self-expanding or they may be expanded by other influences such as a balloon expander.
One example of a stent procedure is the implantation of a Urolume endoprosthesis to treat a urinary tract disorder such as benign prostatic hyperplasia (BPH), a urethral stricture (e.g. a bulbar urethral stricture) or detrusor external sphincter dyssynergis (DESD). It is believed that approximately 35 million men over the age of 50 suffer from BPH or other disorders potentially treatable by a stent procedure. While complications associated with a stent procedure are rare, it is sometimes desirable to remove an in vivo stent.
The removal of a wire stent from the urethra of a patient is a tedious and time consuming procedure. A foreign body extractor or alligator clip is typically used to grasp one region of the stent. Such devices may grasp only a single region of the stent at one time. Once the stent is grasped, the apparatus then can be used to pull the stent from the tissue. Some wire stents are woven or braided from independent wires. It is sometimes required to remove such a stent in a wire by wire fashion, particularly when there is substantial tissue ingrowth.
Other stent retrieval devices are used in cardiac and other surgical procedures. U.S. Pat. Nos. 5,411,507; 5,868,753; 6,027,508 6,027,509; 6,159,219; and 6,187,016 describe various stent retrieval devices.
The present invention comprises a foreign body retrieval apparatus having a handle, and an axially elongate member having a foreign body capturing assembly. The elongate member has an inner lumen that is sized and shaped to receive a viewing apparatus.
The apparatus also includes a substantially tubular member with an inner lumen that is sized and shaped to receive the elongate member. The handle, elongate member and tubular member are operatively associated with each other to move between i) an open position with the foreign body capturing assembly capable of receiving a foreign body, and ii) a closed position with the foreign body capturing assembly capable of controlling the foreign body.
The apparatus also includes a sheath having an inner lumen that is sized and shaped to afford sliding passage of the tubular member and the elongate member while in the closed position.
Preferably, the sheath is substantially cylindrical. In one embodiment, the outer diameter and length are sized and shaped to afford transurethral passage of the sheath from the external meatus of the urethra to the bladder of a male patient.
In one embodiment, the foreign body capturing assembly comprises a plurality of tines. Each tine has an inclined portion and a foreign body engagement portion. Preferably, the tines are constructed to be resiliently biased toward the open position. Preferably, the handle and tubular member are arranged so that movement toward the closed position causes the distal end of the tubular member to engage the inclined portions of the tines to cam the tines toward the closed position.
The foreign body extractor is particularly suitable for retrieving a stent, particularly a wire stent assembled from independent, nonattached wires. In one embodiment of the foreign body extractor, the foreign body engagement portions comprise hooks at distal ends of the tines situated so that the foreign body capturing assembly is capable of engaging a plurality of spaced regions of the stent substantially simultaneously. Preferably, each hook includes a concave surface that is sized and shaped to engage a wire of the stent.
In a preferred embodiment, the foreign body capturing assembly comprises three tines projecting about one hundred and twenty degrees relative to each other when viewed in a plane substantially perpendicular to the elongate axis of the elongate member, so that the stent may be grasped and collapsed in a substantially symmetrical fashion. More preferably, the hooks are substantially flat hooks situated at an angle that is substantially perpendicular to the elongate axis of the elongate member.
In addition to affording axial sliding motion of the elongate member and tubular member within the sheath, the lumen of the sheath also preferably is constructed to afford rotation of the elongate member and tubular member about the elongate axis of the elongate member.
Preferably, the handle and tubular member are arranged so that movement toward the closed position causes the distal end of the tubular member to engage the inclined portion of the tines to cam the tines toward the closed position, and in the open position, at least a portion of the tines and the foreign body engagement portions project radially beyond the outer diameter of the sheath.
When the foreign body comprises an in vivo wire stent having a radius (e.g. a self-expanding UroLume endoprosthesis), movement toward the closed position while the hooks are engaged with spaced wires on the stent preferably causes the stent to collapse radially so that relative axial movement between i) the tubular member, elongate member and engaged stent, and ii) the sheath results in removal of substantially all of the stent from the body.
In one embodiment, the handle comprises a thumb ring and a finger ring movable between adjacent and remote positions. The thumb ring is preferably assembled to be substantially stationary relative to the axially elongate member. In this embodiment, the finger ring is operatively associated with the tubular member so that movement of the finger member relative to the thumb ring from the remote toward the adjacent position moves the tubular member distally in a direction substantially parallel to the axis of the elongate member.
While the present invention is particularly suitable for retrieving stents, it is also noted that the device may also be used to capture a foreign body by surrounding or caging the foreign body (e.g. something within the bladder the should be removed). In the closed position, the distal ends of the arms are preferably substantially adjacent each other so that a foreign body may be captured by the arms and removed from the body through the sheath.
In another aspect, the present invention comprises a method of removing an in vivo stent. The method comprises the steps of: providing an assembly comprising a handle, and an axially elongate member having a stent capturing member, receiving at least a portion of the elongate member within a substantially tubular member, inserting a viewing apparatus into an inner lumen of the elongate member; receiving a portion of the tubular member within a sheath having a distal end; inserting the sheath into a tubular passage of a patient, viewing the in vivo stent with the viewing apparatus; moving the stent capturing member toward an open position with the handle, engaging the stent with the stent capturing member, then moving the stent capturing member toward a closed position, and causing relative axially movement between i) the tubular member and elongate member with the engaged stent, and ii) the distal end of the sheath to slide the stent from the patient.
Preferably, the step of causing relative axially movement between i) the tubular member and elongate member with the engaged stent, and ii) distal end of the sheath removes substantially all of the stent from the patient at once.
In one embodiment for treating a male, the step of inserting the sheath into a tubular passage of a patient includes the step of inserting the sheath from the external urethral meatus to a prostate region of a patient.
In another embodiment, the step of engaging the stent with the stent capturing member comprises the step of rotating the elongate member and tubular member about the axis of the elongate member while in the open position.
Preferably, the step of causing relative axially movement between i) the tubular member and elongate member with the engaged stent, and ii) distal end of the sheath to slide the stent from the patient includes the step of: applying traction to the tubular member and elongate member with the engaged stent and sliding the sheath distally relative to the handle.
The method may also include the step of resecting ingrown tissue away from the in vivo stent.